Sliver App Bar

Sliver

	// vim: syntax=dart
@override
  Widget build(BuildContext context) {
    var width = MediaQuery.of(context).size.width;
    final theme = Theme.of(context);
    return Scaffold(
      // ANCHOR Extended App Bar
      body: NestedScrollView(headerSliverBuilder: (
        BuildContext context,bool innerBox){
          return <Widget>[SliverAppBar(
                elevation: 5,
                shape: RoundedRectangleBorder(
                  borderRadius : BorderRadius.only(
                    bottomLeft: Radius.circular(30),
                    bottomRight: Radius.circular(30)
                  )
                ),
                backgroundColor: Colors.orangeAccent,
                expandedHeight: 200,
                floating: true,
                forceElevated: true,
                pinned: true,
                title: Row(mainAxisAlignment: MainAxisAlignment.spaceAround,children: [
                  Icon(Icons.add,color: Colors.transparent,),
                  Container(
                    margin: EdgeInsets.only(right:width/2 - 130),
                    child: Text("Today's Task")
                    ),
                  Container(
                    height : 25,
                    width : 25,
                    decoration : BoxDecoration(
                      border : Border.all(color:Colors.white),
                  ),
                  alignment: Alignment.center,
                  child: Text(ind.toString(),style: TextStyle(fontSize: 14),),
                  ),
                ],
                  ),
                  flexibleSpace:Container(
                    margin: EdgeInsets.only(top : 75),
                    child: FlexibleSpaceBar(
                                   centerTitle: true,
                                  background: Column(
                                    children: <Widget>[
                                      Icon(Icons.arrow_drop_down),
                                      Theme(
                                      data : theme.copyWith(
                                        accentColor: Colors.white,// highlted color
                                          textTheme: theme.textTheme.copyWith(
                                            headline5: theme.textTheme.headline5.copyWith(
                                              fontSize: 40
                                            ), //other highlighted style
                                            bodyText2: theme.textTheme.bodyText2.copyWith(
                                              fontSize: 27
                                            ), //not highlighted styles
                                      )),
                                      // ANCHOR Number Picker
                                      child: NumberPicker.horizontal(initialValue: ind, minValue: 1, maxValue: 31, onChanged: (n){
                                              setState(() {
                                                ind = n;
                                              });
                                            },
                                            ),
                                          
                                      ),
                                          Icon(Icons.arrow_drop_up),
                                    ],
                                  ),
                                ),

                  ),

              ),
          ];
        },
        // 
       body: Center(child: Text("Sample"),)),
    );
  }